I tend to stay away from doing much near Home ports for the very reason you state when ppl come into ur fights. Even then, If randoms do join, generally they are pretty reasonable when asking them not to sink/cap.
Shame you had this happen to you. This is actually one of the better communities Ive seen since the early days of WoW for me. But you will get bad eggs here and there. Don't give up the sails just yet.
Fair Winds and Following Seas too ya.